Horizons Region waterways are highly polluted and a 20-year plan to get the situation up to scratch is too slow, Water and Environmental Care Association lawyer Tom Bennion told the Environment Court in Wellington on Monday.
"By any measure that's a modest timeline. It requires large trade-offs from the community. We would prefer decisive action."
The association was one of the parties joining the Fish and Game Council and Environmental Defence Society to ask the court for rulings on the way Horizons Regional Council has been giving consent for intensive farming under its One Plan.
The parties began making their case on Monday, in a hearing that could take two to five days. It is before Environment Court Judge Craig Thompson, who was judge in the final One Plan hearings. Also present were commissioners K Edmonds and J Mills.
At issue is the amount of nitrogen the region's dairy farms have been allowed to leach into waterways and ground water. Mr Bennion said it was appropriate to put numbers around the amount that can be leached.